When colloidal particles are dispersed in a photopolymerizable monomer, repulsive force between the colloidal particles is induced by the combination of the colloidal particles and the monomer, and as such, spontaneous three-dimensional lattice may be formed by the particles and subsequently lattice structure may be solidified by the photopolymerization of monomers. However, the formed structure may have poor color sharpness due to white scattering, and show sharp color development when the reflection angle of light is different from the observation angle thereof, thus deteriorating the aesthetic properties of materials and thereby lowering the value of use thereof as a coating material.
In the related arts, a method of manufacturing photonic crystals in various shapes, including hemispherical patterning of photonic crystals using a photopolymerizable colloidal dispersion medium has been introduced. For example, photopolymerizable monomer solution containing colloidal particles may be patterned on the surface of a substrate and cured to thereby produce a structure having a photonic crystal pattern. However, any configuration for improving the color sharpness of the cured structure has not been provided.
In addition, in the related arts, a coating composition, which is improved in temperature resistance, moistureproofness, fingerprint resistance and washability, has been introduced. The coating composition may comprise a photocurable hard coating agent including a colloidal inorganic oxide, an additive including silica, and a photoinitiator. However, the coating composition may not provide any configuration that may increase aesthetic properties of materials by improving the color sharpness of the coating product.